Consider the following energy levels of a hypothetical atom:

Question

Consider the following energy levels of a hypothetical atom:

E₄ −1.51 × 10⁻¹⁹ J

E₃ −7.11 × 10⁻¹⁹ J

E₂ −1.25 × 10⁻¹⁸ J

E₁ −1.75 × 10⁻¹⁸ J

(a) What is the wavelength of the photon needed to excite an electron from E₁ to E₄?

(answer in m)

(b) What is the energy (in joules) a photon must have in order to excite an electron from E₂ to E₃? (answer in J)

(c) When an electron drops from the E₃ level to the E₁ level, the atom is said to undergo emission. Calculate the wavelength of the photon emitted in this process. (answer in m)

Answer 1

These can all be solved using the relation

E_final - E_initial = h x c / λ where h is Planck's constant (6.63 x 10^-34 m² kg / s), c is the speed of light (3.00 x 10⁸ m/s), and λ the wavelength in meters. To calculate λ, solve the equation for λ and substitute the other terms.

To calculate energy, just subtract the two energy levels.